City were far from convincing and the win did little to ease the pressure on manager Hughes as speculation continues to mount about his future.
They struggled to beat the Black Cats who have now won only once in their last ten league and cup matches.
While the slapstick defending from both teams made painful viewing for Hughes, whose side lost 3-0 at Tottenham in midweek, and Sunderland's Steve Bruce, it proved a gripping game for both sets of supporters who certainly received value for money.
City were quick out of the blocks taking a fourth-minute lead when Carlos Tevez and Craig Bellamy linked well to set up Roque Santa Cruz who side-footed home the opening goal from six yards.
And it got better for City as they doubled their advantage in the 12th minute when Bellamy was bundled off the ball by Nyron Nosworthy and Tevez stepped up to score from the penalty spot, his ninth goal of the season.
If City thought it was going to be a walk in the park they were mistaken as Sunderland were back on level terms midway through the opening period.
Central-defender John Mensah stayed upfield following a corner to head home his first goal of the season from a cross by Andy Reid as City's defence was static.
Worse was to follow when City's defence failed to clear a corner and Jordan Henderson rifled home the loose ball into the roof of the net from ten yards to make it 2-2.
Shell-shocked City went ahead in the 35th minute when Shaun Wright-Phillips squared the ball from the right and Bellamy was left in acres of space on the left of the box to pick his spot with a well-placed shot past keeper Marton Fulop.
Hungarian Fulop came to Sunderland's rescue early in the second half making a terrific save to deny Tevez.
City were stunned again midway through the second period when substitute Kenwyne Jones beat Vincent Kompany to a Henderson cross to head home from four yards.
But in an amazing match, City soon regained the lead and sealed victory when Santa Cruz slid in his second goal of the game from a couple of yards out after being set up by Pablo Zabaleta and Gareth Barry.
Sunderland's hopes of drawing level were dashed in stoppage time when Michael Turner was sent off for elbowing Barry in the face.